基于非线性效应的多波长掺铒光纤激光器的研究

发布时间：2018-03-17 21:44

本文选题：多波长激光器　切入点：非线性效应　出处：《哈尔滨工业大学》2015年博士论文　论文类型：学位论文

【摘要】：密集波分复用技术是提升光纤通信速率与容量的有效途径,其实现的关键技术是产生多波长激光信号。传统的方法是采用半导体激光器阵列产生多波长激光信号,但这种阵列光源因为系统庞大、结构复杂以及成本较高等缺点,一定程度地限制了通信容量的提升。相比之下,掺铒光纤激光器作为产生多波长激光信号的光源,具有结构简单、体积小、重量轻及成本低等优点,被认为是大容量光纤通信系统中最具潜力的光源,因此对其开展相关研究具有非常重要的意义。然而,一般情况下的掺铒光纤激光器存在剧烈的模式竞争效应,无法实现多波长激光输出。为解决这一问题,本论文围绕非线性光学效应抑制模式竞争的方法,开展了基于受激布里渊散射、四波混频、受激布里渊散射与非线性光学环形镜组合、受激布里渊散射与四波混频组合的多波长掺铒光纤激光器的理论与实验研究。其主要的研究内容如下:(1)通过结合描述掺铒光纤的速率方程与受激布里渊散射耦合方程的解析解,建立了基于受激布里渊散射效应的多波长掺铒光纤激光器的理论模型,数值模拟了掺铒光纤泵浦功率、布里渊泵浦功率及波长对此类多波长掺铒光纤激光器的输出波长数量的影响,并对其进行了相应的实验验证,数值模拟与实验结果吻合较好。(2)提出了利用两注入泵浦光信号的方法,使基于四波混频的多波长掺铒光纤激光器实现波长间隔任意可调。实验观测了这种多波长激光器输出波长数量对注入泵浦波长、功率、波长间隔及掺铒光纤泵浦功率的依赖关系,并数值模拟了这些依赖关系,实验与数值模拟结果具有较好的一致性。(3)针对基于受激布里渊散射的多波长掺铒光纤激光器输出幅度平整性不好、输出数量调节不便利的现象,提出了利用受激布里渊散射与非线性光学环形镜组合的技术方案。在此方案基础上,建立了这种多波长掺铒光纤激光器的理论模型,数值模拟了掺铒光纤泵浦功率、四分之一波片角度和输入偏振状态对此类多波长激光器输出的波长数量与幅度平整性的影响,并进行了实验验证,数值模拟获得的变化规律与实验结果相一致。(4)提出了利用受激布里渊散射与四波混频组合的技术方案,使掺铒光纤激光器获得多波长输出。在此基础上,建立了这种多波长掺铒光纤激光器的理论模型,该模型通过利用受激布里渊散射与四波混频效应组合的非线性极化强度表达式,推导了描述这两种非线性效应的功率与相位耦合方程。根据建立的-I-模型,本论文进行了相应的数值模拟以及实验验证,分析了掺铒光纤泵浦功率、布里渊泵浦功率对输出多波长数量的影响。本论文的研究结果对于完善基于这些非线性效应的多波长掺铒光纤激光器的机理模型、优化此类多波长掺铒光纤激光器设计、促进其实际应用具有重要的指导意义。
[Abstract]:Dense wavelength Division Multiplexing (DWDM) is an effective way to improve the speed and capacity of optical fiber communication. The key technology is to produce multi-wavelength laser signal, the traditional method is to use semiconductor laser array to generate multi-wavelength laser signal. However, because of the large system, complex structure and high cost, this kind of array light source limits the communication capacity to a certain extent. In contrast, erbium-doped fiber laser is used as the light source to produce multi-wavelength laser signal. With the advantages of simple structure, small size, light weight and low cost, it is considered as the most potential light source in large capacity optical fiber communication system. In general, erbium-doped fiber lasers have intense mode competition effect, so it is impossible to realize multi-wavelength laser output. In order to solve this problem, this paper focuses on the method of suppressing mode competition due to nonlinear optical effects. Based on stimulated Brillouin scattering, four-wave mixing, stimulated Brillouin scattering and nonlinear optical annular mirror, Theoretical and experimental study of a multi-wavelength erbium-doped fiber laser with stimulated Brillouin scattering and four-wave mixing. The main contents of this study are as follows: 1) Analytical solutions of the rate equation and stimulated Brillouin scattering coupling equation of erbium-doped fiber are described by combining the rate equation and the stimulated Brillouin scattering equation. A theoretical model of multi-wavelength erbium-doped fiber laser based on stimulated Brillouin scattering effect is established. The pump power of erbium-doped fiber is numerically simulated. The effects of Brillouin pump power and wavelength on the number of output wavelengths of this kind of multiwavelength erbium-doped fiber lasers are verified by experiments. The numerical simulation is in good agreement with the experimental results. The multiwavelength erbium-doped fiber laser based on four-wave mixing can be adjusted at arbitrary wavelength intervals. The number of output wavelengths of this multi-wavelength laser is experimentally observed for the injection pump wavelength and power. The dependence of wavelength interval and the pump power of erbium-doped fiber is simulated numerically. The experimental results are in good agreement with the numerical simulation results. (3) aiming at the phenomenon that the output amplitude of multi-wavelength erbium-doped fiber laser based on stimulated Brillouin scattering is not smooth enough and the output quantity is not convenient to adjust, Based on this scheme, the theoretical model of the multi-wavelength erbium-doped fiber laser is established, and the pump power of erbium-doped fiber is numerically simulated. The effects of 1/4 wave plate angle and input polarization state on the wavelength number and amplitude levelness of this kind of multiwavelength laser are verified by experiments. The variation law obtained by numerical simulation is consistent with the experimental results. (4) A technical scheme of combining stimulated Brillouin scattering and four-wave mixing is proposed to obtain multi-wavelength output of erbium-doped fiber laser. The theoretical model of this multi-wavelength erbium-doped fiber laser is established. The nonlinear polarization intensity is expressed by using the combination of stimulated Brillouin scattering and four-wave mixing effect. The power and phase coupling equations describing the two nonlinear effects are derived. According to the established -I- model, the corresponding numerical simulation and experimental verification are carried out, and the pump power of erbium-doped fiber is analyzed. The effects of Brillouin pump power on the output number of multi-wavelength erbium doped fiber lasers are studied in this paper. The results of this paper can improve the mechanism model of multi-wavelength erbium-doped fiber lasers based on these nonlinear effects and optimize the design of such multi-wavelength erbium-doped fiber lasers. It has important guiding significance to promote its practical application.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TN248

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